Dan Siemon

Tag: Networking

  • Book: An Engineering Approach to Computer Networking

    A while ago the Packet Pushers had Geoff Huston on as a guest in the future of networking series. There are lots of good ideas and contrarian opinions in that podcast episode – go listen to it. During the episode, Geoff mentioned a book that had a big influence on him called An Engineering Approach…

  • Book: The Art of Network Architecture

    I recently finished reading The Art of Network Architecture. If I remember correctly, I found out about this book during an episode of the Packet Pushers where the author participated. I ordered the book based on the promise of discussion of SDN use cases and SDN networking in general. It turns out that this wasn’t…

  • In-band Network Telemetry

    I’ve done a bit of research into P4 recently. Figuring out if the IP-[TCP/UDP] mono-culture is here stay is a long-term interest of mine and P4 is perhaps one way to break that mono-culture. One of the use cases presented for P4 is in-band telemetry. None of this really requires P4 but it’s interesting to…

  • Detecting Failure

    Part 1: Internet Redundancy, Or Not Part 2: Redundant Connections to a Single Host? In the last post I discussed how devices like your laptop and mobile phone are computing devices with multiple Internet connections not all that different from a network with multiple connections. The anecdote about Skype on a mobile phone reconnecting a…

  • Redundant Connections to a Single Host?

    Part 1: Internet Redundancy, Or Not Previously I wrote about how true redundancy for Internet connections is only available to Internet providers and very large enterprises. This post continues from there. I would guess that the fact that it’s not possible to get redundant Internet access is a big surprise to people who haven’t look…

  • Internet Redundancy, Or Not

    Imagine you are a business that wants to have redundant connections to the Internet. Given the importance of an active Internet connection for many businesses this is a reasonable thing for an IT shop or business owner to ask for. One could also consider the serious home gamer who can’t risk being cut off as…

  • BPF, Linux and Networking

    Linux 3.13 was just released. As always there are lots of interesting new features but two stand out to me: nftables and cls_bpf. Nftables is the replacement for iptables. It offers a new syntax, looks easier to use and has a simpler kernel implementation through the use of a JITed BFP-like language instead of dedicated…

  • nftables

    Nftables, the new firewall infrastructure designed to replace iptables in the Linux kernel has just been merged. If you are a Linux kernel packet geek this is pretty exciting stuff. Unlike iptables, which has kernel code to parse and classify all kinds of different traffic types, nftables relies on a small BPF like bytecode language.…

  • Packet Queueing Article Published in Linux Journal

    Some time ago I started writing a blog post to help myself better understand where packets can be queued within the Linux kernel. This relates to my long time interest in optimizing for latency and experimenting with the kernel’s QoS features. By the time I was ready to hit the publish button, the blog post…

  • An introduction to SDN

    The video below is a very interesting overview of the goals behind SDN vs the typical discussion about the technical aspects.